United States military personnel and dependents who have tested seropositive for the Human Immunodeficiency Virus (HIV) are given medical examinations and treatment at Walter Reed Army Medical Center. Subjects are also invited to participate in a research protocol to study the natural history of HIV infection, conducted by the Walter Reed Army Institute of Research. An oral health research component conducted by NIDR is a part of this natural history study. More than 800 subjects were enrolled in the oral health component from 1989 to 1994 and returned approximately every six months for re- evaluation of their oral health status and for other tests and procedures. About 40% of these persons have had 3 or more exams and 13% had at least 5 exams. The oral component includes examinations by an oral medicine specialist for soft tissue lesions, periodontal conditions (gingival bleeding, plaque and calculus indices, presence of inflammation/destruction of interdental papillae, and presence of erythematous banding), and caries, and the acquisition of plaque, saliva, and mucosal smears for tests for candida. A questionnaire obtains information from subjects on demographic characteristics, health care utilization, oral symptoms, oral hygiene practices, and tobacco and alcohol intake. Information is obtained from the main Walter Reed Army Institute study on other factors such as disease staging, CD4+ counts, and medications. The purpose of this study is to: (1) study oral manifestation (periodontal, oral mucosal, salivary, and presence of oral pathogens) as early indicators of changes in immune status and systemic disease progression; (2) study the impact of behavior (i.e., dental hygiene, tobacco, dental utilization) and behavioral change on changes in periodontal health and oral mucosal health of HIV infected persons; (3) develop a paradigm for the progression of periodontal disease and other oral diseases and conditions in HIV infected persons; and (4) examine the relationship of self-assessment of oral and systemic health and clinically assessed periodontal, oral mucosal, and systemic health.